Another form of the same class is the κάδοs, with its diminutive καδίσκος, which is represented by the Latin _situla_, or bucket, the latter word being the one usually employed by archaeologists. It is a form easily to be recognised in Greek art, but is more usually found in metal-work, _e.g._ in Etruscan and Italian bronzes, than in pottery.[558] The painted situlae, of which a few late examples from Italian tombs exist, are obviously direct imitations of the metal buckets, and in some cases actually have movable bronze handles attached. The situla appears to have been used not only for keeping wine in the cellar, but for serving it up at banquets[559]; the word is also used by Aristophanes for a voting-urn and a well-bucket.[560] In Latin the uses were probably distinguished, _cadus_ denoting a wine-jar, _situla_ a water-bucket. Athenaeus obviously goes astray in regarding it as a drinking-cup. A vase which was used almost exclusively for carrying water was the =Hydria=, as is implied by its name (ὑδρία, from ὕδωρ). Its most essential characteristic is the possession of three handles, a large one at the back for carrying when empty, and two small horizontal handles at the sides for carrying when full. The shape of the body varies at different periods; in the B.F. period the shoulder is flat and marked off by a sharp angle from the body (Fig. 34); but about the beginning of the fifth century this is replaced by a form with more rounded outline and smaller handle at the back, generally known for the sake of distinction as a _kalpis_ (Fig. 35). In the earlier variety (of which some R.F. examples are known) there are always two subjects, one forming a frieze on the shoulder, the other treated more in the manner of a metope on the body; they are invariably enclosed in frames or panels, as on the “black-bodied” amphorae. Sometimes a third subject in the form of a frieze of animals is added below. In the earlier stages of the B.F. period this form is seldom found, except in a class known as the “Caeretan hydriae,” distinguished (as far as concerns their shape) by their round, plump body, as also by the florid character of their ornament and curious treatment of subjects (p. 353). These vases were closely copied by the Etruscans. The _kalpis_ form sometimes occurs with black figures, but only in small late specimens, chiefly found in Rhodes. In the vases of Southern Italy the _kalpis_ is fairly popular, but the body is more cylindrical and the foot higher. [Illustration: FIG. 34. HYDRIA.]